Dogs with Cushing’s disease benefit most from a diet that’s high in protein, moderate in fat, and rich in fiber. Because excess cortisol reshapes your dog’s metabolism in specific ways, the right food choices can help manage symptoms like weight gain, muscle wasting, elevated blood sugar, and that characteristic potbelly. There’s no single prescription diet made specifically for Cushing’s, but understanding what the disease does to your dog’s body makes it straightforward to choose the right foods.
Why Cushing’s Changes Your Dog’s Nutritional Needs
Cushing’s disease (hyperadrenocorticism) floods your dog’s body with cortisol, a stress hormone that breaks down muscle protein for energy, drives up blood sugar, promotes fat storage around the abdomen, and increases appetite. Over time, this leads to muscle loss, insulin resistance, high cholesterol, and a weakened immune system. Your dog may also drink and urinate excessively, which affects mineral balance.
Every dietary choice for a Cushing’s dog works against one or more of these effects. High-quality protein counteracts muscle breakdown. Fiber slows sugar absorption. Controlled fat intake prevents further weight gain and protects the liver, which is already under strain from elevated cortisol. The goal isn’t a radical diet overhaul but a deliberate shift toward foods that support what cortisol is actively undermining.
Protein: The Most Important Priority
Cortisol is catabolic, meaning it breaks down your dog’s lean muscle to convert protein into glucose. This is why Cushing’s dogs often develop a potbellied appearance: they’re losing muscle mass in their limbs and back while storing fat centrally. A diet with highly digestible, high-quality protein helps counteract this breakdown.
Look for foods where a named animal protein (chicken, turkey, beef, fish) is the first ingredient, not a grain or byproduct meal. Dogs with Cushing’s generally need more protein than a typical maintenance diet provides. If your dog also has kidney disease, which sometimes coexists with Cushing’s, protein levels need to be balanced more carefully with your vet’s input, but for most Cushing’s dogs, generous protein is beneficial.
Fat, Fiber, and Carbohydrates
Moderate fat is the target. Cushing’s dogs commonly develop high blood lipid levels, and excess dietary fat can worsen this while also adding calories your dog doesn’t need. Avoid high-fat commercial foods and especially table scraps with visible fat or greasy cooking residue. That said, some fat is essential for nutrient absorption and coat health, so you’re not trying to eliminate it entirely.
Fiber is one of the most useful tools in a Cushing’s diet. Soluble fiber slows the absorption of glucose from food, helping to blunt the blood sugar spikes that cortisol already promotes. It also adds bulk to meals, which helps satisfy your dog’s increased appetite without adding significant calories. Foods with added pumpkin, sweet potato (in moderation), or oat fiber work well. Many “weight management” commercial dog foods have higher fiber content and can be a reasonable starting point.
For carbohydrates, choose complex sources over simple ones. Brown rice, barley, and legumes release glucose slowly compared to white rice or corn-heavy formulas. Some owners opt for low-glycemic or grain-free formulas, though grain-free diets have their own considerations and aren’t automatically better.
Foods to Avoid
High-sodium foods are particularly problematic. Cortisol causes the body to retain sodium, which contributes to increased thirst, urination, and potentially high blood pressure. Avoid processed dog treats, deli meats, cheese, and any human food with added salt. When adding broth to your dog’s food for palatability, use only low-sodium versions.
High-oxalate foods also deserve caution. Dogs with Cushing’s have an elevated risk of developing calcium oxalate bladder stones. Foods rich in oxalates, such as spinach, peanuts, sweet potato in large amounts, and tofu, can contribute to stone formation and are best limited or avoided. Interestingly, restricting dietary calcium itself doesn’t appear to reduce this risk, so you don’t need to worry about cutting calcium-containing foods.
Sugary treats and simple carbohydrates should be off the table. Your dog’s body is already struggling with blood sugar regulation, and adding quick-burning sugars makes that worse.
Healthy Treats and Snacks
Cushing’s dogs are perpetually hungry thanks to cortisol’s appetite-boosting effects, so having a list of safe, low-calorie snacks is essential for your sanity and your dog’s waistline. The American Animal Hospital Association recommends these whole food options for dogs:
- Green beans (raw or cooked), one of the best options for bulk with minimal calories
- Carrot sticks (raw)
- Cucumber slices (raw)
- Zucchini slices (raw)
- Apple slices (no seeds)
- Banana slices (small amounts, as these are higher in sugar)
- Cantaloupe or watermelon (small slices)
These are high in water and fiber, low in calories, and contain no added sodium or fat. Green beans and cucumber are especially good because they’re filling without meaningfully affecting blood sugar. You can freeze green beans or carrot sticks for a longer-lasting chew.
Supplements Worth Knowing About
Two supplements have gained attention specifically for Cushing’s management: melatonin and lignans. Both are used most commonly in atypical Cushing’s cases (where sex hormones rather than just cortisol are elevated), but some veterinarians recommend them for typical cases as well.
The University of Tennessee College of Veterinary Medicine has published dosing guidelines for these. Melatonin is typically given at 3 mg twice daily for dogs under 30 pounds and 6 mg twice daily for dogs over 30 pounds. SDG lignans (derived from flaxseed hulls) are dosed at roughly one milligram per pound of body weight per day. HMR lignans, another form, range from 10 to 40 mg per day depending on the dog’s size. These are available over the counter, but you should discuss them with your vet before starting, especially if your dog is on other Cushing’s medications.
Omega-3 fatty acids from fish oil can help with skin and coat issues, which are common in Cushing’s dogs, and may have mild anti-inflammatory benefits. Antioxidant-rich foods or supplements can support immune function that cortisol suppresses.
Choosing a Commercial Dog Food
No major pet food manufacturer makes a diet specifically labeled for Cushing’s disease. Instead, you’re looking for a food that hits the right profile: high protein, moderate to low fat, higher fiber, and low sodium. Several categories of commercial food come close.
Weight management formulas often have reduced fat and increased fiber, which checks two important boxes. Senior dog formulas sometimes have a similar profile with added joint support. Some veterinary therapeutic diets designed for diabetes or liver support overlap with what Cushing’s dogs need, though none is a perfect match for every case.
When reading labels, check the guaranteed analysis for crude protein (aim for 30% or higher on a dry matter basis for kibble), crude fat (below 12 to 15% on a dry matter basis is reasonable), and crude fiber (5% or higher). The ingredient list should start with a named animal protein, not a grain or byproduct. Avoid formulas where corn, wheat, or soy are the first ingredients, as these are quickly converted to glucose.
Feeding Schedule and Portions
Splitting your dog’s daily food into two or three smaller meals rather than one large feeding helps maintain steadier blood sugar throughout the day. This is especially important because cortisol already pushes blood sugar upward, and a large single meal creates an additional spike.
Portion control matters more than usual because Cushing’s dogs will act ravenous and beg convincingly. Use a measuring cup or kitchen scale rather than eyeballing portions. If your dog has gained weight, a gradual reduction of 10 to 15% of their current caloric intake, combined with the healthy snacks listed above to manage hunger, is a reasonable starting approach. Weigh your dog every two to three weeks and adjust based on the trend rather than making dramatic cuts.
Fresh water should always be available. Cushing’s dogs drink and urinate more than normal, and restricting water can lead to dangerous dehydration. If the excessive drinking bothers you, the volume will typically decrease once treatment brings cortisol levels under better control.